Housings of this type are preferably used as gear housings, whereby the coaxial bores receive a shaft which carries a gear and which is supported in both housing sections. To this end, both housing sections must be mutually positioned so that the axes of the coaxial bores are positioned relative to each other with high accuracy. This high accuracy of position has so far been achieved with a fitting pin connection. The housing sections are thereby first preprocessed, then bolted together and, subsequently, the pin bores and the further bores are made. However, this process results in a very high manufacturing cost and, furthermore, must be interrupted for the bolting together of the housing sections:
Drilling tools are known (DE-PS 36 10 016. DE-PS 41 20 436), which include several cutting plates of different diameter which are axially spaced. Stepped bores can be manufactured in a single process step with such drilling tools.